THE ROLE OF ABDOMINAL ADIPOSITY AND INSULIN-RESISTANCE IN DYSLIPIDEMIA OF CHRONIC-RENAL-FAILURE

The atherogenic profile of high triglyceride, reduced high-density lip oprotein (HDL) cholesterol, and small low-density lipoprotein particle size found in patients on chronic hemodialysis is known to be associa ted with insulin resistance and abdominal obesity in the general popul ation. To assess the influence of insulin resistance and abdominal adi posity on the lipid profile in subjects on hemodialysis, intravenous g lucose tolerance test and dual-energy x-ray absorptiometry were perfor med in 26 nondiabetic subjects on hemodialysis and compared with 22 no ndiabetic control subjects matched for age, sex, and body mass index. Subjects on hemodialysis were found to have higher triglyceride (133 m g/dL [95% confidence interval, 115 to 159 mg/dL] v 97 mg/dL [95% confi dence interval, 80 to 124 mg/dL]; P < 0.05), lower HDL cholesterol (36 +/- 3 mg/dL v 51 +/- 4 mg/dL [mean +/- SEM]; P < 0.01), enhanced insu lin response to glucose (2.72 +/- 0.28 mUL(-1)min per mg dL(-1) v 1.67 +/- 0.22 mUL(-1)min per mg dL(-1); P < 0.01), and reduced sensitivity to the action of insulin (2.24 min(-1) per mUL(-1) min [95% confidenc e interval, 1.86 to 2.75 min(-1) per mUL(-1) min] v 4.17 min(-1) per m UL(-1) min [95% confidence interval, 2.95 to 5.9 min(-1) per mUL(-1) m in]; P < 0.01) than the control subjects. Abdominal adiposity measured by dual-energy x-ray absorptiometry (2,004 +/- 210 g v 2,163 +/- 198 g [mean +/- SEM]; P = NS) and percentage of body fat distributed to th e abdomen (10.5% +/- 0.3% v 9.7% +/- 0.5% [mean +/- SEM]; P = NS) did not differ between the two groups. Subjects on hemodialysis were insul in resistant, but unlike control subjects, their lipid profile was not predicted by their insulin sensitivity. Abdominal adiposity was assoc iated with a deteriorating lipid profile and insulin resistance in sub jects on hemodialysis, as it was in control subjects. The presence of renal failure resulted in additional insulin resistance and a higher t riglyceride level in the leaner subjects on hemodialysis compared with control subjects with similar levels of abdominal fat. In the more ob ese subjects, insulin sensitivity and triglyceride level did not diffe r between the two groups of subjects, although HDL cholesterol level r emained low in subjects on hemodialysis. In conclusion, insulin resist ance in subjects on hemodialysis did not directly account for their ab normal lipid profile. The negative impact of abdominal adiposity on th e metabolic profile was preserved in subjects on hemodialysis, but the presence of renal failure itself resulted in insulin resistance in th e leaner subjects and dyslipidemia in all subjects on hemodialysis com pared with control subjects of comparable abdominal adiposity. (C) 199 7 by the National Kidney Foundation Inc.